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  • 比较标准的读取数据语句asp.net c#

    protected void Page_Load(object sender, EventArgs e)
    {
    string str_provider = "Provider=Microsoft.Jet.OLEDB.4.0;";
    string str_source = "Data Source=" + MapPath("../App_Data/data.mdb");
    string str_conn = str_provider + str_source;

    OleDbConnection conn;
    OleDbCommand comm;
    OleDbDataReader datar;

    string str_sql = "select c1 from data ";

    conn = new OleDbConnection(str_conn);
    conn.Open();
    comm = new OleDbCommand(str_sql, conn);

    datar = comm.ExecuteReader();
    while (datar.Read())
    {
    reader.InnerHtml += datar["c1"].ToString() + "<br/>";
    }
    conn.Close();
    }

    ----------------------------------------优化1

    protected void Page_Load(object sender, EventArgs e)
    {
    OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + MapPath("../App_Data/data.mdb"));
    conn.Open();
    OleDbCommand cmd = new OleDbCommand("select c1 from data", conn);
    OleDbDataReader odr = cmd.ExecuteReader();
    while (odr.Read())
    {
    reader.InnerHtml += odr["c1"].ToString() + "<br/>";
    }
    conn.Close();
    }

    ------------------------------------------------------优化2

    protected void Page_Load(object sender, EventArgs e)
    {
    OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|datadirectory|data.mdb");
    conn.Open();
    OleDbCommand cmd = new OleDbCommand("select c1 from data", conn);

    using (OleDbDataReader odr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
    {
    while (odr.Read())
    {
    reader.InnerHtml += odr["c1"].ToString() + "<br/>";
    }

    }

    }

    <div id="reader" runat="server" style="border: 1px solid black">

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  • 原文地址:https://www.cnblogs.com/houweidong/p/12319338.html
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